Bus fleet replacement optimization considering life-cycle carbon emissions and total cost of ownership

Abstract

To explore the benefits and potential of electricity and hydrogen as alternative fuels for regular buses, a mixed-integer planning model was constructed to determine the schedule optimization scheme for bus fleet replacement. The model was based on the comprehensive analysis of carbon emissions and the total cost of ownership from a life cycle perspective. Using actual operational data of buses powered by diesel, natural gas, hybrid, plug-in electric, and hydrogen fuel cells, the effects of uncertainty in the power mix, acquisition cost, hydrogen production, and hydrogen usage cost on the fleet replacement schedule were explored. The results reveal that plug-in electric buses are currently the optimal choice for bus fleet replacement. Given the current level of vehicle technology and hydrogen production, hydrogen fuel cell buses(HFCEBs)are advisable during bus fleet replacement. Until the production of blue or green hydrogen becomes commercially viable, promoting HFCEBs on a large scale by extending financial subsidies is not recommended. The proposed method can help authorities identify optimized bus fleet replacement options under specific constraints and desired objectives to promote green and sustainable development.

Keywords

bus fleet replacement / life-cycle carbon emissions / total cost of ownership / mixed-integer programming / alternative fuel / electric bus / hydrogen fuel cell bus